Four U.S. F-22 stealth fighters fly over Osan Air Base in Pyeongtaek, South Korea, Wednesday, Feb. 17, 2016. Four U.S. F-22 stealth fighters flew over South Korea on Wednesday in a clear show of power against North Korea, a day after South Korea’s president warned of the North’s collapse amid a festering standoff over its nuclear and missile ambitions. (AP Photo/Lee Jin-man)

One of four U.S. F-22 stealth fighters flies over Osan Air Base in Pyeongtaek, South Korea, Wednesday, Feb. 17, 2016. Four U.S. F-22 stealth fighters flew over South Korea on Wednesday in a clear show of power against North Korea, a day after South Korea’s president warned of the North’s collapse amid a festering standoff over its nuclear and missile ambitions. (AP Photo/Lee Jin-man)

U.S. Air force military police stands guard near the one of four U.S. F-22 stealth fighter after landing at Osan Air Base in Pyeongtaek, South Korea, Wednesday, Feb. 17, 2016. Four U.S. F-22 stealth fighters flew over South Korea on Wednesday in a clear show of power against North Korea, a day after South Korea’s president warned of the North’s collapse amid a festering standoff over its nuclear and missile ambitions. (AP Photo/Lee Jin-man)